Will a 3.5 liter engine from 1999 Chrysler Concorde fit into 2002 Isuzu trooper?

No, a 3.5L engine from a 1999 Chrysler Concorde will almost certainly not fit into a 2002 Isuzu Trooper. The engine bays, mounting points, and ancillary components (like the transmission, wiring harness, and exhaust system) are completely different between those two vehicles. Even if you could somehow physically cram the engine in, it would be an incredibly complex and impractical project, requiring extensive fabrication and modification. It's not a swap that's even remotely feasible for most people.